#include <iostream>
using namespace std;
int gcd(int x,int y){

    return y==0?x:gcd(y,x%y);

}
int main()
{
    int n,a,b;
    cin>>n;
    while(n--)
    {
        cin>>a>>b;
        int c = 2*b;

        while(gcd(a,c)!=b){
            c+=b;
        }

        cout<<c<<endl;
    }

    return 0;
}